Question

Mention the two principles through which Lamarck explained his ideas.

Answer 1

One of Lamark's principles is that over time use of an organ strengthens it while disuse causes it to deteriorate. Basically the idea that vestigial organs are present.

The other of Lamarck's principles is that acquired characteristics can be passed down from generation to generation. This, however, is wrong as characteristics that get passed down are genetic rather than solely phenotypic. An example of this would be plastic surgery. Just because the person fixed their nose, it doesn't mean their child will inherit the fixed nose.